(function() {
  // A minilanguage for instantiating linked CodeMirror instances and Docs
  function instantiateSpec(spec, place, opts) {
    var names = {},
      pos = 0,
      l = spec.length,
      editors = [];
    while (spec) {
      var m = spec.match(
        /^(\w+)(\*?)(?:='([^\']*)'|<(~?)(\w+)(?:\/(\d+)-(\d+))?)\s*/,
      );
      var name = m[1],
        isDoc = m[2],
        cur;
      if (m[3]) {
        cur = isDoc
          ? CodeMirror.Doc(m[3])
          : CodeMirror(place, clone(opts, { value: m[3] }));
      } else {
        var other = m[5];
        if (!names.hasOwnProperty(other)) {
          names[other] = editors.length;
          editors.push(CodeMirror(place, opts));
        }
        var doc = editors[names[other]].linkedDoc({
          sharedHist: !m[4],
          from: m[6] ? Number(m[6]) : null,
          to: m[7] ? Number(m[7]) : null,
        });
        cur = isDoc ? doc : CodeMirror(place, clone(opts, { value: doc }));
      }
      names[name] = editors.length;
      editors.push(cur);
      spec = spec.slice(m[0].length);
    }
    return editors;
  }

  function clone(obj, props) {
    if (!obj) return;
    clone.prototype = obj;
    var inst = new clone();
    if (props)
      for (var n in props) if (props.hasOwnProperty(n)) inst[n] = props[n];
    return inst;
  }

  function eqAll(val) {
    var end = arguments.length,
      msg = null;
    if (typeof arguments[end - 1] == 'string') msg = arguments[--end];
    if (i == end) throw new Error('No editors provided to eqAll');
    for (var i = 1; i < end; ++i) eq(arguments[i].getValue(), val, msg);
  }

  function testDoc(name, spec, run, opts, expectFail) {
    if (!opts) opts = {};

    return test(
      'doc_' + name,
      function() {
        var place = document.getElementById('testground');
        var editors = instantiateSpec(spec, place, opts);
        var successful = false;

        try {
          run.apply(null, editors);
          successful = true;
        } finally {
          if (!successful || verbose) {
            place.style.visibility = 'visible';
          } else {
            for (var i = 0; i < editors.length; ++i)
              if (editors[i] instanceof CodeMirror)
                place.removeChild(editors[i].getWrapperElement());
          }
        }
      },
      expectFail,
    );
  }

  var ie_lt8 = /MSIE [1-7]\b/.test(navigator.userAgent);

  function testBasic(a, b) {
    eqAll('x', a, b);
    a.setValue('hey');
    eqAll('hey', a, b);
    b.setValue('wow');
    eqAll('wow', a, b);
    a.replaceRange('u\nv\nw', Pos(0, 3));
    b.replaceRange('i', Pos(0, 4));
    b.replaceRange('j', Pos(2, 1));
    eqAll('wowui\nv\nwj', a, b);
  }

  testDoc('basic', "A='x' B<A", testBasic);
  testDoc('basicSeparate', "A='x' B<~A", testBasic);

  testDoc(
    'sharedHist',
    "A='ab\ncd\nef' B<A",
    function(a, b) {
      a.replaceRange('x', Pos(0));
      b.replaceRange('y', Pos(1));
      a.replaceRange('z', Pos(2));
      eqAll('abx\ncdy\nefz', a, b);
      a.undo();
      a.undo();
      eqAll('abx\ncd\nef', a, b);
      a.redo();
      eqAll('abx\ncdy\nef', a, b);
      b.redo();
      eqAll('abx\ncdy\nefz', a, b);
      a.undo();
      b.undo();
      a.undo();
      a.undo();
      eqAll('ab\ncd\nef', a, b);
    },
    null,
    ie_lt8,
  );

  testDoc('undoIntact', "A='ab\ncd\nef' B<~A", function(a, b) {
    a.replaceRange('x', Pos(0));
    b.replaceRange('y', Pos(1));
    a.replaceRange('z', Pos(2));
    a.replaceRange('q', Pos(0));
    eqAll('abxq\ncdy\nefz', a, b);
    a.undo();
    a.undo();
    eqAll('abx\ncdy\nef', a, b);
    b.undo();
    eqAll('abx\ncd\nef', a, b);
    a.redo();
    eqAll('abx\ncd\nefz', a, b);
    a.redo();
    eqAll('abxq\ncd\nefz', a, b);
    a.undo();
    a.undo();
    a.undo();
    a.undo();
    eqAll('ab\ncd\nef', a, b);
    b.redo();
    eqAll('ab\ncdy\nef', a, b);
  });

  testDoc('undoConflict', "A='ab\ncd\nef' B<~A", function(a, b) {
    a.replaceRange('x', Pos(0));
    a.replaceRange('z', Pos(2));
    // This should clear the first undo event in a, but not the second
    b.replaceRange('y', Pos(0));
    a.undo();
    a.undo();
    eqAll('abxy\ncd\nef', a, b);
    a.replaceRange('u', Pos(2));
    a.replaceRange('v', Pos(0));
    // This should clear both events in a
    b.replaceRange('w', Pos(0));
    a.undo();
    a.undo();
    eqAll('abxyvw\ncd\nefu', a, b);
  });

  testDoc('doubleRebase', "A='ab\ncd\nef\ng' B<~A C<B", function(a, b, c) {
    c.replaceRange('u', Pos(3));
    a.replaceRange('', Pos(0, 0), Pos(1, 0));
    c.undo();
    eqAll('cd\nef\ng', a, b, c);
  });

  testDoc('undoUpdate', "A='ab\ncd\nef' B<~A", function(a, b) {
    a.replaceRange('x', Pos(2));
    b.replaceRange('u\nv\nw\n', Pos(0, 0));
    a.undo();
    eqAll('u\nv\nw\nab\ncd\nef', a, b);
    a.redo();
    eqAll('u\nv\nw\nab\ncd\nefx', a, b);
    a.undo();
    eqAll('u\nv\nw\nab\ncd\nef', a, b);
    b.undo();
    a.redo();
    eqAll('ab\ncd\nefx', a, b);
    a.undo();
    eqAll('ab\ncd\nef', a, b);
  });

  testDoc('undoKeepRanges', "A='abcdefg' B<A", function(a, b) {
    var m = a.markText(Pos(0, 1), Pos(0, 3), { className: 'foo' });
    b.replaceRange('x', Pos(0, 0));
    eqCharPos(m.find().from, Pos(0, 2));
    b.replaceRange('yzzy', Pos(0, 1), Pos(0));
    eq(m.find(), null);
    b.undo();
    eqCharPos(m.find().from, Pos(0, 2));
    b.undo();
    eqCharPos(m.find().from, Pos(0, 1));
  });

  testDoc('longChain', "A='uv' B<A C<B D<C", function(a, b, c, d) {
    a.replaceSelection('X');
    eqAll('Xuv', a, b, c, d);
    d.replaceRange('Y', Pos(0));
    eqAll('XuvY', a, b, c, d);
  });

  testDoc('broadCast', 'B<A C<A D<A E<A', function(a, b, c, d, e) {
    b.setValue('uu');
    eqAll('uu', a, b, c, d, e);
    a.replaceRange('v', Pos(0, 1));
    eqAll('uvu', a, b, c, d, e);
  });

  // A and B share a history, C and D share a separate one
  testDoc('islands', "A='x\ny\nz' B<A C<~A D<C", function(a, b, c, d) {
    a.replaceRange('u', Pos(0));
    d.replaceRange('v', Pos(2));
    b.undo();
    eqAll('x\ny\nzv', a, b, c, d);
    c.undo();
    eqAll('x\ny\nz', a, b, c, d);
    a.redo();
    eqAll('xu\ny\nz', a, b, c, d);
    d.redo();
    eqAll('xu\ny\nzv', a, b, c, d);
  });

  testDoc('unlink', 'B<A C<A D<B', function(a, b, c, d) {
    a.setValue('hi');
    b.unlinkDoc(a);
    d.setValue('aye');
    eqAll('hi', a, c);
    eqAll('aye', b, d);
    a.setValue('oo');
    eqAll('oo', a, c);
    eqAll('aye', b, d);
  });

  testDoc('bareDoc', "A*='foo' B*<A C<B", function(a, b, c) {
    is(a instanceof CodeMirror.Doc);
    is(b instanceof CodeMirror.Doc);
    is(c instanceof CodeMirror);
    eqAll('foo', a, b, c);
    a.replaceRange('hey', Pos(0, 0), Pos(0));
    c.replaceRange('!', Pos(0));
    eqAll('hey!', a, b, c);
    b.unlinkDoc(a);
    b.setValue('x');
    eqAll('x', b, c);
    eqAll('hey!', a);
  });

  testDoc('swapDoc', "A='a' B*='b' C<A", function(a, b, c) {
    var d = a.swapDoc(b);
    d.setValue('x');
    eqAll('x', c, d);
    eqAll('b', a, b);
  });

  testDoc('docKeepsScroll', "A='x' B*='y'", function(a, b) {
    addDoc(a, 200, 200);
    a.scrollIntoView(Pos(199, 200));
    var c = a.swapDoc(b);
    a.swapDoc(c);
    var pos = a.getScrollInfo();
    is(pos.left > 0, 'not at left');
    is(pos.top > 0, 'not at top');
  });

  testDoc('copyDoc', "A='u'", function(a) {
    var copy = a.getDoc().copy(true);
    a.setValue('foo');
    copy.setValue('bar');
    var old = a.swapDoc(copy);
    eq(a.getValue(), 'bar');
    a.undo();
    eq(a.getValue(), 'u');
    a.swapDoc(old);
    eq(a.getValue(), 'foo');
    eq(old.historySize().undo, 1);
    eq(old.copy(false).historySize().undo, 0);
  });

  testDoc('docKeepsMode', "A='1+1'", function(a) {
    var other = CodeMirror.Doc('hi', 'text/x-markdown');
    a.setOption('mode', 'text/javascript');
    var old = a.swapDoc(other);
    eq(a.getOption('mode'), 'text/x-markdown');
    eq(a.getMode().name, 'markdown');
    a.swapDoc(old);
    eq(a.getOption('mode'), 'text/javascript');
    eq(a.getMode().name, 'javascript');
  });

  testDoc('subview', "A='1\n2\n3\n4\n5' B<~A/1-3", function(a, b) {
    eq(b.getValue(), '2\n3');
    eq(b.firstLine(), 1);
    b.setCursor(Pos(4));
    eqCharPos(b.getCursor(), Pos(2, 1));
    a.replaceRange('-1\n0\n', Pos(0, 0));
    eq(b.firstLine(), 3);
    eqCharPos(b.getCursor(), Pos(4, 1));
    a.undo();
    eqCharPos(b.getCursor(), Pos(2, 1));
    b.replaceRange('oyoy\n', Pos(2, 0));
    eq(a.getValue(), '1\n2\noyoy\n3\n4\n5');
    b.undo();
    eq(a.getValue(), '1\n2\n3\n4\n5');
  });

  testDoc('subviewEditOnBoundary', "A='11\n22\n33\n44\n55' B<~A/1-4", function(
    a,
    b,
  ) {
    a.replaceRange('x\nyy\nz', Pos(0, 1), Pos(2, 1));
    eq(b.firstLine(), 2);
    eq(b.lineCount(), 2);
    eq(b.getValue(), 'z3\n44');
    a.replaceRange('q\nrr\ns', Pos(3, 1), Pos(4, 1));
    eq(b.firstLine(), 2);
    eq(b.getValue(), 'z3\n4q');
    eq(a.getValue(), '1x\nyy\nz3\n4q\nrr\ns5');
    a.execCommand('selectAll');
    a.replaceSelection('!');
    eqAll('!', a, b);
  });

  testDoc('sharedMarker', "A='ab\ncd\nef\ngh' B<A C<~A/1-2", function(a, b, c) {
    var mark = b.markText(Pos(0, 1), Pos(3, 1), {
      className: 'cm-searching',
      shared: true,
    });
    var found = a.findMarksAt(Pos(0, 2));
    eq(found.length, 1);
    eq(found[0], mark);
    eq(c.findMarksAt(Pos(1, 1)).length, 1);
    eqCharPos(mark.find().from, Pos(0, 1));
    eqCharPos(mark.find().to, Pos(3, 1));
    b.replaceRange('x\ny\n', Pos(0, 0));
    eqCharPos(mark.find().from, Pos(2, 1));
    eqCharPos(mark.find().to, Pos(5, 1));
    var cleared = 0;
    CodeMirror.on(mark, 'clear', function() {
      ++cleared;
    });
    b.operation(function() {
      mark.clear();
    });
    eq(a.findMarksAt(Pos(3, 1)).length, 0);
    eq(b.findMarksAt(Pos(3, 1)).length, 0);
    eq(c.findMarksAt(Pos(3, 1)).length, 0);
    eq(mark.find(), null);
    eq(cleared, 1);
  });

  testDoc('sharedMarkerCopy', "A='abcde'", function(a) {
    var shared = a.markText(Pos(0, 1), Pos(0, 3), { shared: true });
    var b = a.linkedDoc();
    var found = b.findMarksAt(Pos(0, 2));
    eq(found.length, 1);
    eq(found[0], shared);
    shared.clear();
    eq(b.findMarksAt(Pos(0, 2)), 0);
  });

  testDoc('sharedMarkerDetach', "A='abcde' B<A C<B", function(a, b, c) {
    var shared = a.markText(Pos(0, 1), Pos(0, 3), { shared: true });
    a.unlinkDoc(b);
    var inB = b.findMarksAt(Pos(0, 2));
    eq(inB.length, 1);
    is(inB[0] != shared);
    var inC = c.findMarksAt(Pos(0, 2));
    eq(inC.length, 1);
    is(inC[0] != shared);
    inC[0].clear();
    is(shared.find());
  });

  testDoc('sharedBookmark', "A='ab\ncd\nef\ngh' B<A C<~A/1-2", function(
    a,
    b,
    c,
  ) {
    var mark = b.setBookmark(Pos(1, 1), { shared: true });
    var found = a.findMarksAt(Pos(1, 1));
    eq(found.length, 1);
    eq(found[0], mark);
    eq(c.findMarksAt(Pos(1, 1)).length, 1);
    eqCharPos(mark.find(), Pos(1, 1));
    b.replaceRange('x\ny\n', Pos(0, 0));
    eqCharPos(mark.find(), Pos(3, 1));
    var cleared = 0;
    CodeMirror.on(mark, 'clear', function() {
      ++cleared;
    });
    b.operation(function() {
      mark.clear();
    });
    eq(a.findMarks(Pos(0, 0), Pos(5)).length, 0);
    eq(b.findMarks(Pos(0, 0), Pos(5)).length, 0);
    eq(c.findMarks(Pos(0, 0), Pos(5)).length, 0);
    eq(mark.find(), null);
    eq(cleared, 1);
  });

  testDoc(
    'undoInSubview',
    "A='line 0\nline 1\nline 2\nline 3\nline 4' B<A/1-4",
    function(a, b) {
      b.replaceRange('x', Pos(2, 0));
      a.undo();
      eq(a.getValue(), 'line 0\nline 1\nline 2\nline 3\nline 4');
      eq(b.getValue(), 'line 1\nline 2\nline 3');
    },
  );
})();
